1. Field of the Invention
The present invention relates to a connection apparatus for connecting a digital or analog subscriber line of a communication network to a communication device of a subscriber.
2. Description of the Related Art
When a subscriber of a digital communication network such as an ISDN wants to connect his/her analog communication device to the digital communication network, the analog communication terminal must be connected to the subscriber line of the digital communication network through a terminal adapter (TA).
The TA has, as an interface to a personal computer, a digital port such as RS-232C, a digital port (S/T point interface in an ISDN) for connecting a digital device such as a digital telephone, and an analog port (modular jack) for connecting a conventional analog telephone or G3-FAX. Some TAs have a plurality of analog ports. With the use of TA, two arbitrary types of communication/speech communication selected from personal computer communication, digital telephone, analog telephone, FAX, and the like can be performed through an ISDN.
FIG. 1 shows the connection form of a general TA. Reference numeral 100 denotes a TA for transmitting/receiving data/speech data to/from a digital communication line such as an ISDN via a line interface; 102, a digital port connected to a personal computer; 103, a digital port connected to a digital communication device such as a digital telephone; 104, an analog port connected to an analog telephone or FAX; and 105, an analog port like the analog port 104. In this example, the TA has two analog ports.
In the arrangement shown in FIG. 1, when the digital line is used, the communication rate of personal computer communication can be raised, and additionally, a telephone or FAX can be used while performing personal computer communication.
The TA shown in FIG. 1 is connected to one ISDN line having two communication channels. Some private branch exchanges (including key telephones) allow 2xc3x97n terminals to simultaneously communicate by connecting a plurality of (n) ISDN lines.
Some other private branch exchanges are connected to both a digital line such as an ISDN line and an analog line.
One of the convenient functions of such communication is a calling party number notification (caller ID) function. Upon reception of an incoming call, this function serves to notify the called party of the telephone number of the caller and is effectively used to avoid unwanted calls.
The ISDN as a digital network has long supported this calling party number notification function. For example, the INS 64 service of NTT is providing this function free. Most digital devices such as a digital telephone that are connected to the ISDN are compatible with this function. These devices include displays such as LCDs (liquid crystal displays) and have functions of displaying the calling party number upon reception of an incoming call and storing this calling party number to use as data for redialing.
The PSTN (Public Switched Telephone Network) as an analog network is already providing this service in USA, Canada, or England. Even in Japan, this service is planned to start soon, and analog telephones for PSTN are being developed.
However, although the above-described general TA or private branch exchange has an analog port for connecting an analog device, the analog device connected to the analog port is not notified of the calling party number.
For this reason, even when an analog device having an existing calling party number notification function is connected, this function is wasteful, and the existing resource cannot be effectively used.
Conversely, even when a PSTN line as an analog line and an ISDN terminal as a digital terminal are connected to a private branch exchange, the ISDN terminal is not notified of the calling party number which has been notified from the PSTN line upon reception of an incoming call.
It is an object of the present invention to notify an analog terminal of information which has been notified from a digital subscriber line using a digital signal.
It is another object of the present invention to notify a digital terminal of information which has been notified from an analog subscriber line using an analog signal.
Alternatively, a digital signal is received from a digital subscriber line, and an analog signal converted from the received digital signal is sent to a communication device in a procedure of calling the communication device.
In the present invention, an analog signal is received from an analog subscriber line, and a digital signal corresponding to the analog signal received from the analog subscriber line is sent to the communication device in a procedure of calling the communication device.
According to the present invention, there is provided an information sending method for an analog terminal connection apparatus which sends, to an analog terminal having a function of receiving an analog signal modulated according to the calling party number from the network upon reception of an incoming call, the analog signal modulated according to information corresponding to the analog terminal and a ringing signal in place of the calling party number.
According to the present invention, there is also provided an analog terminal connection apparatus for connecting an analog terminal having a function of receiving an analog signal modulated according to the calling party number upon reception of an incoming call, comprising modulated signal sending means for sending, to the analog terminal, an analog signal modulated according to information corresponding to the analog terminal in place of the calling party number, and ringing signal sending means for sending a ringing signal to the analog terminal, or a storage medium which stores a control program for the analog terminal connection apparatus.
The analog modulated signal is sent, e.g., during the OFF period of the ringing signal which is intermittently sent, or before the ringing signal is sent.
According to the present invention, there is also provided an analog terminal connection method comprising inserting, in place of a calling party number, information corresponding to a digital terminal to the position of the calling party number contained in a call reception request code to be sent to the digital terminal and sending the call reception request code to the digital terminal.
According to the present invention, there is also provided a digital terminal connection apparatus comprising call reception request code generation means for inserting, in place of a calling party number, information corresponding to a digital terminal to the position of the calling party number contained in a call reception request code to be sent to the digital terminal, and sending the call reception request code to the digital terminal, or a storage medium which stores a control program for the digital terminal connection apparatus.
The information corresponding to the analog or digital terminal means information unique to the analog or digital terminal (more specifically, information of the connected terminal or extension number). Alternatively, it is information representing the use result or record of the analog or digital terminal (more specifically, communication charge information or communication time information) or, e.g., limitation information (more specifically, destination limitation information, user limitation information, or call limitation upon reception of an incoming call). The call limitation upon reception of an incoming call is information representing whether the terminal is to be called or not depending on the calling party or called party information or information such as a communication attribute detected upon reception of an incoming call. In other words, it is information representing whether the terminal is to be called upon reception of an incoming call, which is set in advance.
Other features and advantages of the present invention will be apparent from the following description take n in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.